Multicolour Observations of the Flickering of V425 Cassiopeia

We report our investigation of the flickering variability of the cataclysmic variable V425 Cas on the basis of observations in 5 bands (UBV RcIc). We find for the flickering source a temperature Tfl ≈ 12000 K, and a radius r ∼ 0.05 − 0.10 R . We analyze the flickering amplitude (∆F ) and search for a relation with the mean flux (Fav). Using all five bands, we find that ∆F ∝ F k av, where k = 1.22±0.12. The value is more similar to that of the symbiotic stars CH Cyg and T CrB, than to that of the cataclysmic varaibale KR Aur.